The magazine air temperature records from nuclear-powered and diesel- powered submarines have been statistically analyzed to obtain the probable thermal exposure to be found on these types of boats. The information is divided into the temperature expectancies for the two submarine classes because of the possibility that thermally they may be dissimilar. Effort has been made to eliminate information from compartments influenced by the engine room. This report includes more than 13,000 data points from four boats. The boats were assigned to the First, Second, Sixth, and Seventh Fleets from 1964 through 1969.